Chiou Guang-Yuh, Fong Jim C
Institute of Biochemistry, National Yang-Ming University, Taipei, Taiwan, Republic of China.
J Cell Biochem. 2005 Feb 15;94(3):627-34. doi: 10.1002/jcb.20338.
The combined effect of prostaglandin F2alpha (PGF2alpha) and cAMP on glucose transport in 3T3-L1 adipocytes was examined. In cells pretreated with PGF2alpha and 8-bromo cAMP for 8 h, a synergy between these two agents on glucose uptake was found. Insulin-stimulated glucose transport, on the other hand, was only slightly affected. The synergistic effect of these two agents was suppressed in the presence of cycloheximide and actinomycin D. In concord, immunoblot and Northern blot analyses revealed that GLUT1 protein and mRNA levels were both increased in cells pretreated with both PGF2alpha and 8-bromo cAMP, greater than the additive effect of each agent alone. The synergistic action of PGF2alpha with 8-bromo cAMP to enhance glucose transport was inhibited by GF109203X, a selective protein kinase C (PKC) inhibitor. In addition, in cells depleted of diacylglycerol-sensitive PKC by prolonged treatment with 4beta-phorbol 12beta-myristate 13alpha-acetate, a PKC activator, the synergistic effects of PGF2alpha and 8-bromo cAMP on glucose transport and GLUT1 mRNA accumulation were both abolished. Taken together, these results indicate that PGF2alpha may act with cAMP in a synergistic way to increase glucose transport, probably through enhanced GLUT1 expression by a PKC-dependent mechanism.
研究了前列腺素F2α（PGF2α）和环磷酸腺苷（cAMP）对3T3-L1脂肪细胞葡萄糖转运的联合作用。在用PGF2α和8-溴环磷酸腺苷预处理8小时的细胞中，发现这两种物质对葡萄糖摄取具有协同作用。另一方面，胰岛素刺激的葡萄糖转运仅受到轻微影响。在存在放线菌酮和放线菌素D的情况下，这两种物质的协同作用受到抑制。与此一致，免疫印迹和Northern印迹分析显示，在用PGF2α和8-溴环磷酸腺苷预处理的细胞中，葡萄糖转运蛋白1（GLUT1）的蛋白质和mRNA水平均升高，且高于每种物质单独作用的累加效应。PGF2α与8-溴环磷酸腺苷协同增强葡萄糖转运的作用被选择性蛋白激酶C（PKC）抑制剂GF109203X抑制。此外，在用PKC激活剂4β-佛波醇12β-肉豆蔻酸酯13α-乙酸盐长期处理使二酰甘油敏感型PKC耗竭的细胞中，PGF2α和8-溴环磷酸腺苷对葡萄糖转运和GLUT1 mRNA积累的协同作用均被消除。综上所述，这些结果表明PGF2α可能与cAMP协同作用以增加葡萄糖转运，可能是通过PKC依赖的机制增强GLUT1的表达。
